Heat exchanger

ABSTRACT

A substantially four-sided housing which forms a chamber therewithin, the housing being open on two opposite sides. A tube nest is replaceably disposed within the chamber, the nest comprising a plurality of coolant tubes each of which tubes has a 180*-bend midway between opposite open ends thereof. A waterhead encloses the open tube ends which are all arrayed at one of the open sides of the housing. The waterhead has inlet and outlet apertures therein for admitting coolant into and from the open tube ends. The housing further includes inlet and outlet fluid plenums at either ends thereof with ports therein for admitting and venting fluid to and from the heat exchanger. Also, walls of the exchanger structure have means for directing fluid away therefrom and into the tube nest.

United States Patent Howe [151 3,656,544 [451 Apr. 18, 1972 [54] HEAT EXCHANGER Primary Examiner-Charles Sukalo Assistant Examiner-Theophil W. Streule Attorney-Carl R. Horten, David W. Tibbott and Bernard J. Murphy [57] ABSTRACT A substantially four-sided housing which forms a chamber therewithin, the housing being open on two opposite sides. A tube nest is replaceably disposed within the chamber, the nest comprising a plurality of coolant tubes each of which tubes has a l80-bend midway between opposite open ends thereof. A waterhead encloses the open tube ends which are all arrayed at one of the open sides of the housing. The waterhead has inlet and outlet apertures therein for admitting coolant into and from the open tube ends. The housing further includes inlet and outlet fluid plenums at either ends thereof with ports therein for admitting and venting fluid to and from the heat exchanger. Also, walls of the exchanger structure have means for directing fluid away therefrom and into the tube nest.

15 Claims, 3 Drawing Figures This invention pertains to heat exchangers for fluids, and in particular to a one-pass, fluid heat exchanger which requires a minimum of machining in the fabrication of the housing thereof having a replaceable tube nest, and having means for inhibiting a leakage or bypass of fluid along the tube nest.

In the prior art, heat exchangers ordinarily comprise housings which require considerable internal machining to precisely accommodate appropriate tube nests; this requirement entails an unwarranted manufacturing expense. Also, known heat exchangers lack means for inhibiting a fluid bypass of the nest. Further, in the prior art heat exchangers it is required to seal coolant tubes at opposite sides of the nest, while they have no means for diffusing any flow of fluid which tends to bypass the nest. These prior art limitations yield inefficient, albeit expensive, heat exchangers.

It is an object of this invention, therefore, to set forth a heat exchanger having a markedly improved structure. It is another object of this invention to design sucha heat exchanger structure which comprises an open-sided housing, having spacedapart fluid inlet and outlet ports, formed of joined side and end walls which cooperate to define an exchange chamber therewithin; 'a tube nest replaceably disposed within the chamber, the nest having a plurality of tubes for conducting coolant through the heat exchanger, each of the tubes opening at either ends thereof on one open side of the chamber; and including means for directing fluid from at least one of the housing walls into the nest.

A feature of this invention comprises a substantially foursided housing which defines a chamber therewithin in which a tube nest is replaceably disposed. The tube nest is formed of a plurality of coolant tubes each of which has a 180 bend therein so that each pen end of each tube is disposed on one side of the nest. Walls of the exchanger have arcuate, recessed surfaces effective for inhibiting a bypass of fluid along the nest and for redirecting fluid away from the walls and into the nest.

Further objects and features of this invention will become more apparent by reference to the following description, taken in conjunction with the accompanying figures, in which:

FIG. 1 is a discontinuous, side elevational view, partly in cross-section, of an embodiment of the invention;

FIG. 2 is also a discontinuous, end-wise, elevational view of the FIG. 1 embodiment of the heat exchanger, taken along section 2-2; of FIG. 1, this figure being in full cross-section; and

FIG. 3 is a transverse, cross-sectional view of the heat exchanger embodiment taken along section 33 of FIG. 2.

As shown in the figures an embodiment of a heat exchanger according to the invention comprises a housing 12 having two end walls 14 joined with two side walls 16, all of which walls together define an exchange chamber 18 therewithin. Housing 12 has two open sides 20 and 22. Chamber 18 is supplied fluid from an inlet plenum 24 which is joined to housing 12 and an outlet plenum 26 receives heat exchanged fluid which has transversed the chamber 18. Inlet plenum 24 has a fluid inlet port 28, and outlet plenum 26 has a fluid outlet port 30, the ports being provisioned for through-communication with a fluid machine, such as a gas compressor, for instance.

A tube nest 32 is replaceably confined within chamber 18, and is formed of a plurality of tubes 34 each of which has a plurality of cooling vanes 36 fixed thereabout. Each tube has a 180 bend portion 38 midway between the open tube ends 40 thereof. The bend portions 38 project outwardly from chamber 18 and are enclosed by a cover 42. Cover 42 is replaceably fixed to the housing 12 by ordinary fastening means (not shown).

Cover 42 has a plurality of first arcuate surfaces 44 and a plurality of transverse, second arcuate surfaces 46 the configurations of which specifically complement the bend portions 38. However, surfaces 44 and 46 are spaced from bend portions 38 so that fluid which tends to bypass the tube nest 32 is conducted between these surfaces and the bend portions, is diffused in its flow path and redirected into the tube nest on flow paths transverse to a normal, given fluid flow path which extends linearly between ports 28 and 30. This novel feature greatly enhances the heat exchange efficiency. Side walls 16 also have means for redirecting fluid passing therealong between ports 28 and 30. Walls 16 have a plurality of contiguous concave recesses 48 extending between plenums 24 and 26. Any fluid bypassing the tubes 34 is directed, by the concave surfaces, from walls 16 back into the tube nest.

The open tube ends 40 are all sealed in a tube sheet 52, and a waterhead 54 encloses the open tube ends and is bolted to the tube sheet 52. Accordingly, the tubes 34, tube sheet 52, and waterhead 54 comprise a replaceable, unitized assembly. A plurality of bolts 55 (only one is shown) secure the assembly to the housing 12. The waterhead has a plurality spaced-apart walls or dividers 56 which form a plurality of chambers 58 and 58'. Chambers 58 and 58' cooperate with a coolant inlet aperture 60 and a coolant outlet aperture 62 to pass coolant through the successive paralleled tubes 34 in a direction counter-flow to the fluid passing through the housing 12 between ports 28 and 30.

To replace tube nest 32 for maintenance or repair purposes, it is necessary only to detach and remove the assembled waterhead 54, tube sheet 52, and tubes 34 by removing bolts 55 from the housing 12, and of course the tube sheet 52 and tubes 34 can be unbolted from the waterhead 54 thereafter, if required. It is to be noted that, in accord with my teaching, the housing 12 requires no precision machining to accommodate the tube nest 32 therewithin. So also, each tube is sealed in the exchanger 10 at only one side thereof in that, through the novel use of the bend portions 38, both open ends of each tube open on one side of housing 12.

My novel heat exchanger teaches means, in concave recesses 48, for directing fluid away from walls 16 and into nest 32, and means, in surfaces 44 and 46, for diffusing fluid which tends to bypass the nest.

For purposes of explanation only, I have set forth an embodiment of my invention in which walls 16 are defined as side walls, and I have illustrated the embodiment as extending vertically upward from plenum 26. This is wholly arbitrary; walls 16 could as well be top and bottom walls, and either cover 42 or waterhead 54 can comprise the uppermost component of the novel structure.

Those skilled'in this art will appreciate that waterhead 54 and apertures 60 and 62 can conduct a heated or cooled fluid therethrough--to heat or cool fluid communicating betweenports 28 and 30. So also, heated or cooled fluid can be conducted between ports 28 and 30 to heat or cool a fluid conducted through the tubes 34. Accordingly, while I have described my invention in connection with a specific embodiment thereof it isto be clearly understood that this is done only by way of example and not as a limitation to the scope of my invention as set forth in the objects thereof in the accompanying claims.

I claim:

1. A heat exchanger for fluids, comprising:

a housing having spaced-apart fluid inlet and outlet ports formed therein;

said housing also having side and end walls, which cooperatively define an exchange chamber therewithin;

said housing further having a pair of oppositely disposed open sides;

a tube nest replaceably disposed within said chamber intermediate said inlet and outlet ports;

said nest having a plurality of tubes, all tubes of said plurality opening at either ends thereof on one open side of said pair of open sides;

each of said tubes having a -bend portion therein intermediate said either ends thereof;

a cover, replaceably fixed to said housing, having an inner surface which defines an interface with said nest, and an oppositely disposed outer surface;

said inner surface having arcuate recesses formed therein, and spaced from said bend portions, to accommodate said bend portions therewithin; wherein said recesses are effective, cooperative with one of said open sides, to define of said cover a fluid-redirecting, ribbed guide open to both said ports and open to fluid, fully therealong, from substantially one end to an opposite end thereof; and

means coupled to said housing for admitting a coolant medium into said nest.

2. A heat exchanger, according to claim 1, wherein:

said bend portion is spaced from the other open side of said pair of open sides.

3. A heat exchanger, according to claim 1, wherein:

said bend portion extends externally from the other open side of said pair of open sides.

4. A heat exchanger, according to claim 1, wherein:

said bend portion both commences at and terminates in the other open side of said pair of open sides.

5. A heat exchanger, according to claim 1, wherein:

said bend portions each have a given, common dimension, major radius, and said recesses each have in common an arcuate-surface radial dimension which is greater than said given radius, said given and greater radii defining at least a first spacial area therebetween for admitting fluid flow therewithin.

6. A heat exchanger, according to claim 5, wherein:

each of said tubes has a given, common dimension, crosssectional diameter, on a plane lying transverse to said major radius, and said recesses each have a spacial dimension extending along said transverse plane which is greater than said diameter, said diameter dimension and said spacial dimension defining at least a second spacial area therebetween for admitting fluid flow therewithin.

7. A heat exchanger, according to claim 1, wherein:

said recesses each have a first arcuate surface, and a second arcuate surface transverse to said first arcuate surface;

said first and second arcuate surfaces being spaced from said bend portions for admitting fluid flow between said bend portions and said arcuate surfaces.

8. A heat exchanger, according to claim 1, wherein:

said side walls both have said means for directing fluid therefrom and into said nest.

9. A heat exchanger, according to claim 7, wherein:

said fluid directing means comprise arcuate wall surfaces extending between said inlet and outlet ports.

10. A heat exchanger, according to claim 8, wherein:

said fluid directing means comprise a plurality of contiguous, concave recesses fonned in surfaces of said side walls which face said nest.

11. A heat exchanger, according to claim 1, wherein:

said coolant-medium-admitting means comprises a waterhead replaceably sealed to said housing at said one side thereof.

12. A heat exchanger, according to claim 11, wherein:

said waterhead has a coolant medium inlet aperture formed therein adjacent to one end of said housing, and a coolant medium outlet aperture formed therein adjacent to an end of said housing opposite said one end.

13. A heat exchanger, according to claim 11, wherein:

said waterhead has a coolant medium inlet aperture formed therein adjacent both to one end of said housing and to said outlet port, and a coolant medium outlet aperture formed therein adjacent both to an end of said housing opposite said one end and to said inlet port.

14. A heat exchanger, according to claim 12, wherein:

said waterhead has means cooperative with said one side to define a plurality of chambers upon said one side to accommodate a conduct of coolant medium through said tubes from said inlet aperture to said outlet aperture.

15. A heat exchanger, according to claim 13, wherein:

said waterhead has means cooperative with said one side to define a plurality of chambers upon said one side to accommodate a conduct of coolant medium through said tubes from said inlet aperture to said outlet aperture. 

1. A heat exchanger for fluids, comprising: a housing having spaced-apart fluid inlet and outlet ports formed therein; said housing also having side and end walls, which cooperatively define an exchange chamber therewithin; said housing further having a pair of oppositely disposed open sides; a tube nest replaceably disposed within said chamber intermediate said inlet and outlet ports; said nest having a plurality of tubes, all tubes of said plurality opening at either ends thereof on one open side of said pair of open sides; each of said tubes having a 180* -bend portion therein intermediate said either ends thereof; a cover, replaceably fixed to said housing, having an inner surface which defines an interface with said nest, and an oppositely disposed outer surface; said inner surface having arcuate recesses formed therein, and spaced from said bend portions, to accommodate said bend portions therewithin; wherein said recesses are effective, cooperative with one of said open sides, to define of said cover a fluid-redirecting, ribbed guide open to both said ports and open to fluid, fully therealong, from substantially one end to an opposite end thereof; and means coupled to said housing for admitting a coolant medium into said nest.
 2. A heat exchanger, according to claim 1, wherein: said bend portion is spaced from the other open side of said pair of open sides.
 3. A heat exchanger, according to claim 1, wherein: said bend portion extends externally from the other open side of said pair of open sides.
 4. A heat exchanger, according to claim 1, wherein: said bend portion both commences at and terminates in the other open side of said pair of open sides.
 5. A heat exchanger, according to claim 1, wherein: said bend portions each have a given, common dimension, major radius, and said recesses each have in common an arcuate-surface radial dimension which is greater than said given radius, said given and greater radii defining at least a first spacial area therebetween for admitting fluid flow therewithin.
 6. A heat exchanger, according to claim 5, wherein: each of said tubes has a given, common dimension, cross-sectional diameter, on a plane lying transverse to said major radius, and said recesses each have a spacial dimension extending along said transverse plane which is greater than said diameter, said diameter dimension and said spacial dimension defining at least a second spacial area therebetween for admitting fluid flow therewithin.
 7. A heat exchanger, according to claim 1, wherein: said recesses each have a first arcuate surface, and a second arcuate surface transverse to said first arcuate surface; said first and second arcuate surfaces being spaced from said bend portions for admitting fluid flow between said bend portions and said arcuate surfaces.
 8. A heat exchanger, according to claim 1, wherein: said side walls both have said means for directing fluid therefrom and into said nest.
 9. A heat exchanger, according to claim 7, wherein: said fluid directing means comprise arcuate wall surfaces extending between said inlet and outlet ports.
 10. A heat exchanger, according to claim 8, wherein: said fluid directing means comprise a plurality of contiguous, cOncave recesses formed in surfaces of said side walls which face said nest.
 11. A heat exchanger, according to claim 1, wherein: said coolant-medium-admitting means comprises a waterhead replaceably sealed to said housing at said one side thereof.
 12. A heat exchanger, according to claim 11, wherein: said waterhead has a coolant medium inlet aperture formed therein adjacent to one end of said housing, and a coolant medium outlet aperture formed therein adjacent to an end of said housing opposite said one end.
 13. A heat exchanger, according to claim 11, wherein: said waterhead has a coolant medium inlet aperture formed therein adjacent both to one end of said housing and to said outlet port, and a coolant medium outlet aperture formed therein adjacent both to an end of said housing opposite said one end and to said inlet port.
 14. A heat exchanger, according to claim 12, wherein: said waterhead has means cooperative with said one side to define a plurality of chambers upon said one side to accommodate a conduct of coolant medium through said tubes from said inlet aperture to said outlet aperture.
 15. A heat exchanger, according to claim 13, wherein: said waterhead has means cooperative with said one side to define a plurality of chambers upon said one side to accommodate a conduct of coolant medium through said tubes from said inlet aperture to said outlet aperture. 